From 25d63eb730b864a72679654f3d378a061c167034 Mon Sep 17 00:00:00 2001
From: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Date: Tue, 11 Jul 2023 23:15:48 +0900
Subject: [PATCH] tracing/probes: Fix to update dynamic data counter if
fetcharg uses it
commit e38e2c6a9efc435f9de344b7c91f7697e01b47d5 upstream.
Fix to update dynamic data counter ('dyndata') and max length ('maxlen')
only if the fetcharg uses the dynamic data. Also get out arg->dynamic
from unlikely(). This makes dynamic data address wrong if
process_fetch_insn() returns error on !arg->dynamic case.
Link: https://lore.kernel.org/all/168908494781.123124.8160245359962103684.stgit@devnote2/
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Link: https://lore.kernel.org/all/20230710233400.5aaf024e@gandalf.local.home/
Fixes: 9178412ddf5a ("tracing: probeevent: Return consumed bytes of dynamic area")
Cc: stable@vger.kernel.org
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
kernel/trace/trace_probe_tmpl.h | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)
diff --git a/kernel/trace/trace_probe_tmpl.h b/kernel/trace/trace_probe_tmpl.h
index 5db3e691392f..c293a607d536 100644
--- a/kernel/trace/trace_probe_tmpl.h
+++ b/kernel/trace/trace_probe_tmpl.h
@@ -206,11 +206,13 @@ store_trace_args(void *data, struct trace_probe *tp, void *rec,
if (unlikely(arg->dynamic))
*dl = make_data_loc(maxlen, dyndata - base);
ret = process_fetch_insn(arg->code, rec, dl, base);
- if (unlikely(ret < 0 && arg->dynamic)) {
- *dl = make_data_loc(0, dyndata - base);
- } else {
- dyndata += ret;
- maxlen -= ret;
+ if (arg->dynamic) {
+ if (unlikely(ret < 0)) {
+ *dl = make_data_loc(0, dyndata - base);
+ } else {
+ dyndata += ret;
+ maxlen -= ret;
+ }
}
}
}